


Holding You With My Voice (And Then Letting You Go)

by Silent-Wordsmith (Shatteredsand)



Series: Don't Dream Too Deep [2]
Category: Supergirl (TV 2015)
Genre: Denial, F/F, Guilt, Hints of praise kink, Hints of voyeurism, Masturbation, Mutual Masturbation, Phone Sex, Pseudo-Incest, Repression, Sister-Sister Incest, The Internet Doesn't Actually Have EVERYTHING, it's not incest if one of them is an alien
Language: English
Status: Completed
Published: 2017-03-11
Updated: 2017-03-11
Packaged: 2018-10-02 20:58:09
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,988
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10227194
Author URL: https://archiveofourown.org/users/Shatteredsand/pseuds/Silent-Wordsmith
Summary: Alex has been back at Stanford for a while. She’s been putting thoughts of Kara to the back of her mind for weeks now, ignoring all the feelings she refuses to acknowledge as she drinks herself into the kind of stupor that allows herself to take another girl to bed, to moan incoherent syllables instead of a name.And, then, Kara calls her.





	

**Author's Note:**

> My poor Ace Soul is drowning in alcohol to keep the smut coming (pun one hundred percent, fully intended).

It’s a Tuesday night, mid-March, and Alex is staying in to study because there’re no good parties to found on an Tuesday night—Alpha Capa Delta sometimes tries, and always fails to deliver; Alex has made the mistake of trying to find a good time at one of their Tuesday parties before—when her phone rings out Kara’s special ringtone. Alex pulls herself away from her textbook, eyes scanning the room for wherever she’d tossed her phone when she got back from class.

She catches it on the last ring, bringing up to her ear with a breathless “Hey.”

“Alex?”

“Yeah, Kara, what’s up?”

A heavy pause. One Alex is used to. Kara has spoken fluent English for years, but, sometimes, there’s still a pause, a delay, as she translates what she _means_ —in Kryptonian—to what she _says_ —in English.  “I can’t do it.”

It’s a whine, and Alex would be more sympathetic if A, she didn’t have finals fast approaching and B, she any idea what Kara was talking about.

“Can’t do what?” Alex breathes out, exasperated. There’s been a lot that Kara thought she couldn’t do, only to find that she could, and do it well. Alex doesn’t mind playing the role of cheerleader, the alien’s personal pep squad for all things human and, therefore, _alien_ to her. But she needs some kind of context or she’s useless, and she doesn’t have the time to be useless right now.

A drawn out silence, different than Kara trying to parse from her first tongue into English—heavier, somehow—Kara’s soft breathing the only sign that she hadn’t hung up.

“I can’t…” Kara trails off, huffs out a heavy sigh, one that Alex thinks might be mortification. “I can’t… _masturbate_.” She finishes quietly, barely audible to the human ear. 

“Oh.” Alex breathes in deep, trying to pretend she doesn’t feel the way she does. This is normal. This is her sister, growing up and asking questions. “I’m _so_ not the person to talk to about this.”

Alex doesn’t trust herself with this, with Kara’s emotional—sexual—vulnerability. Her thoughts still stray to golden blonde hair and bright blue eyes when she needs to get off, her mouth still clamps closed with drunken co-eds to stop herself from moaning the wrong— _right_ —name in the late night/early morning of her meaningless trysts. She isn’t someone who can talk to Kara about this, not objectively, not rationally, not the way Kara deserves.

“Well, I can’t do it myself.” Plaintive, an alien still struggling to understand. It makes Alex ache, with sympathy, with want.

“It’s called the internet, use it.” Battling against the part of her that wants this, wants Kara desperate in her ear, wants Kara to look to her always, for everything. It’s not right. It’s the height of wrong, and Alex is better than that. More, Kara _deserves_ more than that. More than a would-be, should-be, sister who lusts after her. For all she looks like a young adult—for all she looks like someone Alex should be, is allowed to be, attracted to—she’s still just a kid. Someone with fewer years on this planet than a kindergartener—and Alex isn’t allowed to want her the way she does. It’s wrong, and manipulative, and borderline abusive. It’s taking advantage, at best. And Kara deserves so much more than her foster sister whispering vileness in her ear in an attempt to coerce her into feeling the same, broken way Alex does.

“I tried; it doesn’t work.” It’s practically a whimper. Kara so needy as to make every part of Alex ache with the desire to reach out and fix everything that could ever be wrong with the younger girl’s existence. It’s not right, it’s more than an older sibling should want to do. But Alex has never managed to fit Kara into the category of _little_ _sister_ , and it continues to bite her in the ass. There’s nothing Alex doesn’t want to do for Kara, everything: big or small, innocent or sinful, Alex wants it all so long as Kara is smiling, so long as Kara is happy.

“What do you mean it doesn’t work? It’s the internet; it has everything!” Alex needs a way out of this conversation before it goes past the point of no return. The point rapidly approaching as Alex tries not to get involved in this—in Kara’s sexual awakening—and finds herself trapped in the middle of it all the same.

“Does it have an alien category? The real kind, not ambiguously alien that’s completely human except for the weird coloring and affected accent?”

She has a point, however much Alex doesn’t want to admit it. There’s not much realistic alien porn out there—it’s all green body paint and cheap prosthetic horns—nothing like the real aliens, aliens that look and feel like Kara. Not that Alex had looked. Not that Alex’s internet search history had “humanoid alien with super powers; porn hub” all over it. Not that Alex cared whether there were convincing portrayals of aliens and humans having the best sex of their lives with each other. Not that Alex was invested at all.

“I see your point.” Alex reluctantly admits. She doesn’t want to talk about this. Talking about it is dangerous, could lead to Alex saying things she shouldn’t. Things she couldn’t take back. Things that would ruin her and Kara. 

“Can you help me?” So soft in her request. So hesitant. Alex hates that, hates that Kara thinks there’s something—anything—Alex wouldn’t give her. But this is something else, something more than Alex _should_ give.

Her mother’s voice at the back of her mind saying _sister_ , saying _help_ _her_ , saying _she_ _doesn’t_ _understand_ and _you_ _have_ _to_ _help_ , saying _sister sister sister sister_ on endless repeat until Alex felt wrong with every thought, every breath, every curl of her fingers and hitch in her breathing.

“Of course I’ll help you.” It’s instinct to say it, to mean it. Half a decade of being told to help Kara, to be there for Kara, to do anything and everything for Kara. Alex doesn’t know how to say anything else, however much she knows this is a bad idea. A terrible idea. The worst idea.

Helping Kara get off, _listening_ to Kara get off, means that Alex won’t be capable of thinking of anything else. She knows that, accepts that. Buries her own problems—finals fast approaching, the inevitable requisite distance demanded between them, the way this is going to fucking _wreck_ her—and puts Kara first, the way she always does. This is not okay. This is the crossing of a boundary few ever even understand exist, let alone reach. But here, now, Alex stands at the precipice of it, listening to Kara’s quaking breathes, and she can deny her nothing for anything.

“What. What should I do first?” The first tremblings of a question.

That is exactly the kind of question Alex doesn’t need to hear her should-be little sister asking her through the phone. Not like this. Not in a _tell me how you want me to touch myself way_.

Fuck.

“Start slow.” Alex says—orders?—half out of her depth and half desperate to follow her own damn advice as she feels the heat beneath her navel building. “Light touches. Just your stomach, your thighs, maybe your breasts.” A deep inhale, “maybe your nipples, if you think you’ll like it. Focus on what feels good, Kara. It’s about. It’s about feeling good.”

“Mmm.” Kara sighs gently, and Alex wants to throw herself out a window to stop the way that makes her feel. The not unexpected but unwanted gushing in her panties and the clenching in her thighs as he aches for something that isn’t there and never will be. Never can be. “Yeah, okay.”

Alex can’t hear much for a few long moments, but she can hear enough. The slight sound of shifting sheets—shifting clothing?—as Kara follows her directions, the soft breathing of her foster sister as her touches herself—dear gods, Alex is listening to her _touch_ _herself_ —and, if she strains her ears, maybe, the sound of fingertips running over preternaturally smooth skin.

“Are you feeling good?” This is, perhaps, an unnecessary question, closer to something like the phone-sex they definitely aren’t having than an older sibling trying to talk their sister through their first go at masturbation. But Alex wants to know, needs to know; gods above and below damn her for it.

“Yeah.”  Another soft sigh, barely audible but present. Alex hears it. Alex hears it, and Alex clenches on nothing, and Alex wants this to be something it’s not. Alex wants this to be something less than it is.

Alex just. She _wants_.

“Good. Good girl.” Swallows thickly, because she hadn’t meant to say that last part, that part’s definitely not okay, even more than the rest of this. “Are you playing with your nipples?”

“ _Yes_.” A hiss this time, and Alex doesn’t want to imagine her pinching her nipples, pulling at them a little, the way Alex would if she thought she could, but she does. Fuck her to hell and back, she does.

“That’s good.” Alex is struggling to keep her voice even. If she sounds unsteady Kara will get worried, Kara will stop. Alex doesn’t want her to stop. “Now, move a hand down from there, Kara. _Slowly_.”

“Mft.” Kara makes a sound between a moan and a groan and, shit. Shit. Fuck. Alex can’t do this. This is wrong. This is ten times worse than thinking about Kara when she’s with nameless coeds or by herself. This is an active corruption. This is something she can’t do. She can’t, she can’t, she can’t. “ _Alex_.”

She can’t stop.

“Keep going, Kara.” Alex breathes out, hoping that Kara is too distracted to notice the quality of her voice. “Slip into your panties.”

“I’m not, I’m not wearing any.”

Jesus.

Fucking.

 _Christ_.

“Oh. Okay. That’s, that’s good.” That’s so good Alex might actually die. “Touch yourself, touch your cunt.”

Alex doesn’t even know if Kara knows that word; it’s hardly likely to have been on her vocab worksheets. But she seems to get the idea because she’s moaning—she’s _moaning_ —out, “oh, oh!”

“Yeah, that’s it. You’ve got it. You’re doing so good.”

“ _Alex_.” Panted into her ear, painted in desperation, in Kara’s voice, and it’s all Alex can do not reach her hand into her own sopping underwear.

“Yeah? That feel good? You feel good?”

“Rao, yes.”

“Just play with it a little. Run your fingers through the folds, Kara, feel everything.” Feel everything the way she wants to but will never, ever allow herself to.

“It’s good, Alex. It’s _so_ _good_.” Kara says, pitchy and needy and everything Alex has ever wanted to hear from Kara but never even dared to hope for.

The ache between her legs is getting harder to ignore, but this isn’t about her, can’t be about her. This is about Kara. This is about _helping_ Kara. If she touches herself, it’s another line she can’t uncross, another failure to be a good sister—hell, a good person, even—and Alex has enough failures stacking up.

“Are you wet?” Another unnecessary question. Kara sounds wet, she sounds ready. She sounds like Alex could fit two fingers in easy, maybe three.

No, not Alex. Like someone, like someone _else_ , could. Someone definitely not Alex because this is not about _her_.

“So wet.” Kara’s starting to sound a little out of it, a little lost. Like, could accidentally bruise Alex in her need, out of it. Like, would fuck a little too hard—just hard enough for Alex—out of it. Like, inhumanly strong and slightly too fast—the way Alex wants it—out of it.

Alex couldn’t keep her hands off herself if she tried. And, gods, she tried. She tried so hard.

This is wrong, this is wrong, this _wrong_.

This is the worst thing she’s ever done.

But she can’t stop.

Gods, she so wet. She interposes Kara’s sounds over the feeling of her own fingers sliding through her soaked folds, circling her entrance, edging at her clit. Fuck. _Fuck_.

“Touch your clit, the little bump at the top. Can you feel it?” The answer comes in the form of uttered Kryptonian, something Alex is eighty-percent sure is a swear. “There you go, Kara. There you go.”

Alex can feel herself getting closer, just listening, just knowing what Kara is doing. But she knows she can’t come before Kara does, she has to see this through, has to make sure the call is over before she loses herself.

“Rub at it, as hard or as soft as you like, as fast or slow as you like. Experiment with it for me.” Shit, that was out of bounds in the worst kind of way. In a way Kara might notice.

 _For_ _me_.

Like Kara wanted Alex to be the one doing this to her. Like Kara wanted _Alex_.

“Rao, _Alex_.” She doesn’t know exactly what Kara’s doing, but it must be working for her. Must be going exactly right. And Alex gushes again at the idea that she did that, she made Kara feel this way, with her words, her direction, her _care_. However fucked up it might be. “I feel so…”

Kara trails off, unsure of her words, or her feelings, or both, and Alex has never felt closer to coming harder than ever before than she does right now with barely a graze of her fingertips and Kara sounding like that in her ear.

“Close, Kara.” Alex gasps out, beyond caring about morality, about right or wrong or which side of that very thin line she’s on. It’s half finishing her foster sister’s sentence and half just, _telling_. She’s so close, and she going to come so hard, and she needs Kara to go first so Alex can hang up and finish and call back like it was an accident. “You’re gonna come, Kara. You’ve done so good, and you’re gonna come for me.”

_For me._

Again, words she shouldn’t have said, wasn’t supposed to have said, couldn’t stop herself from saying.

A whimpering whine on the other end of the line, Kara as desperate as Alex has ever heard her. More. Hovering over the cusp on her first orgasm. Her first orgasm, the one that Alex had talked her to, the one that Alex was going to bring her over.

“Do it, Kara.” Alex is panting, gasping, groaning, so close and so eager, and so damn _close_. “Come for me.”

And Kara, Kara _does_.

Alex can _hear_ it.

Alex can hear Kara. Kara, crying out “Alex, Alex, _Alex_ , **_Alex_**!”. Kara, moaning out in her native tongue a slew of lilting words that Alex can’t understand. Kara, falling apart under her own hands and Alex’s direction.

The wet sounds of her release, barely caught over the phone’s shitty mic and Kara’s voluminous barely-not-shouts.

Alex can hear _everything_.

And, fuck hanging up and waiting. Fuck pretending it was an accident. Fuck pretending that she’s not coming harder than she ever has in her entire life to the sounds of her foster sister coming like a freight train over the phone.

“God. _Fuck_. God. **_Kara_**!”  Alex doesn’t mean to shout—to _scream_ —but she’s grown too accustomed to the privacy of her dorm. She doesn’t have to answer to Eliza here, she doesn’t have to explain herself to anyone. If she wants to have a screaming orgasm, she can, whenever she wants.

Her hips are still jerking lightly against slack fingers as she comes down, as she tries to level her breathing, as she tries to ignore that this had ever happened. But her body’s quivering, and her chest is heaving, and her hips are still twitching forward like the best orgasm of her life was only a precursor, and Alex knows she’s never going to forget a single second of any of it. Not one second from the moment her phone rang until now, with all of her except her head so ready for the main course after the delicious appetizer. The main course of fucking her foster sister like she’s always wanted. The main course that is _never_ going to come.

Fuck.

Alex looks at her line in the sand, obliterated by her tidal wave of lust and love and _come_ , and tells herself she’s not allowed to cry while Kara’s still on the line.

“Alex?” Kara says, soft again. The need gone, banished either by her orgasm or her concern for her sister—her _sister_ , that’s what Alex is _supposed_ to be—Alex doesn’t know. It doesn’t matter anyway.

“Yeah, Kara, I’m here. Everything’s okay. You did great.”

“Are you sure?” The tremble of uncertainty, the idea that Kara could even question it, almost has Alex opening her mouth to tell her how good she was. How she made Alex come undone with almost just her sounds. How it was so good Alex was helpless against touching herself, getting herself off. How Alex just had an orgasm better than any other she’s ever experienced and it was all because of Kara and how good she was.

But Alex grits her teeth, and Alex bites her tongue, and Alex says “Yeah, Kara. Really knocked it out of the park.” And Alex forces herself to smile, even if Kara can’t see it, and emphatically doesn’t think about who else Kara might come for. Who else might make Kara feel the way Alex just did. “You’ll be a pro in no time.”

And then Alex says her goodbyes to a sated, bone-tired Kara, and Alex hangs up, and Alex masturbates like her own hands and her own memory and her own imagination are ever going to be enough to make her come like Kara just inadvertently did.


End file.
